Men are trained to ignore feelings, but we're human, and we can learn to be with our feelings despite our training. Remember, we have our feelings; they do not have us.
Real feelings, as powerful as they can be, come and go quickly. We can navigate them the way we want to - sometimes skimming the surface, sometimes diving deep. We can often learn to put them aside for the moment and return to them later.
IMO, being betrayed brings on grief, anger, fear, and shame. Those feelings are just responses to the A and to d-day. I've been taught to let them flow through my body. That also lets them flow out of my body, never to return.
3 things to remember: 1) being betrayed bring LOTS of feelings, so it takes a long time to process them. At first, it may seem that you'll never heal, but if you start and keep going, the A-related feelings will almost completely disappear. Triggers are always possible, but they get get less and less frequent (I can't remember the last one for me), and less and less powerful.
2) New events can bring grief, anger, fear, shame, joy, love - so releasing the A-related feelings doesn't mean you'll never feel bad again.
3) The ability to feel awful is the same as the ability to feel joy and love. You can't feel great unless you can feel awful, IMO.
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IMO, R is a process of building an M that serves both of you. You both need to live mindfully and consciously create the M you want.
That means, at the very least, that you have to raise issues as they arise. If you're unhappy with something in your M, it's YOUR job to figure out what you want and to ask for it.
Your W may have another view. If she does, you need to resolve the issue in a way that works for both of you. In successful Rs, issues are addressed; they aren't allowed to fester.
It takes guts to be in an M, to stand up for yourself and to take your W into account, too.
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As you move through R, if you build the new M that serves you both, I think you'll come to recognize how strong and courageous you are, and I think you'll feel enough joy. You'll see that you're getting what you want. For me, at least, getting what I want is enough to resolve my early questions about being a wimp.
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I suggest reading this: http://www.survivinginfidelity.com/healing_library/reconciliation/what-every-wayward-spouse-needs-to-know.asp.
I also suggest printing it off and asking your W to read and discuss it. I suggest saying you found it on the web, without saying your joined SI.
Ask yoru questions. I recommend especially asking the questions that scare you - don't hide from potential deal breakers. Why waste months or years in'R' only to find a deal breaker down the line?